Stamp-mill screen.



D. 0. EN EARL. STAMP MILL SCREEN.

APPLICATION FILED JAN. 25. 1911.

Patented NOV. 14, 1911.

- INVENTOR Darius C. EnEa rl ATTORNEYS COLUMBIA 'PLANDURYAPH (20.,WASHINGTON. D. c.

DARIUS COMSTOCK EN EARL, OF ROLLINSVILLE, COLORADO.

STAMP-MILL SCREEN.

Specification of Letters Patent.

Patented Nov. 14, 1911.

Application filed January 25 1911. Serial No. 604,560.

To all whom it may concern:

Be it known that I, DARIUS C. EN EARL, a citizen of the United States,and a resident of Rollinsville, in the county of Gilpin and State ofColorado, have invented a new and Improved Stamp-Mill Screen, of whichthe following is a full, clear, and exact description.

My invention consists of a'screen to be used in the mortar of a stampmill employed for the wet crushing of the ores of gold and otherprecious metals.

It has for its object to provide a screen of greater capacity andendurance than those heretofore used, and having in addition certainnovel features of construction.

It consists broadly in a number of bars arranged adjacent one anotherbut spaced apart so as to provide openings therethrough, which openingsgradually increase in size to prevent the screen from becoming choked upas the crushed ore is washed therethrough.

In operation, the screen sifts the ore after it has been crushed anddelivers it to the amalgamating plate or table in a sufficientlypowdered condition to insure its retention by the quicksilver with whichtheamalgamating plate is covered.

Reference is to be had to the accompanying drawings forming a part ofthis specification, in which similar characters of reference indicatecorresponding parts in all the views.

Figure 1 is a mortar of a stamp mill, showing the position of my screenwhen in place; Fig. 2 is a vertical sectional view of my milling screen,showing the bars supported by the frame thereof; Fig. '3 is a frontelevation of the screen frame and the bars therein; Fig. 4 is aperspective view of the barswhich make up the mesh of my milling screen,showing the manner in which these bars are held spaced apart from oneanother; and Fig. 5 is a transverse section of one of the bars. I

Numeral 1 designates my stamp mill .creen as a whole, and it consists ofa number of plates or bars 2, each of which is thicker along one of itslongitudinal edges than along the other longitudinal edge. These barsare arranged in a frame, as shown in Fig. 2, with their thick edges atone side or face of the frame, and their thin edges at the other side orface of the frame. In this way the openings or spaces between the bars 2increase in size from one face of the frame to the other. The face ofthe frame having the small ends of the openings I term the receivingface, and the opposite face, on which are the enlarged ends of theopenings between the plates, I term the discharge face of the frame.This frame is indicated at 9. The bars are held spaced apart by means oftransverse projections 3, which are formed preferably by stamping atregular intervals along the length of the bar. These projections form ineffect V-shaped tongues having corresponding grooves 4 of less depththan the tongues on the opposite face of the bar 2. Through thesetongues are arranged openings 5, which receive tie-rods or bolts 6. Theplates and tire-rods when assembled are inclosed by a suitable casing 8,of wood or other suitable material, which contains the frame 9, thelatter consisting of metal bars, angle-shaped in cross-section,.arrangedinside of the boX or casing 8. These angleshaped bars are not as wide asthe faces of the wooden casing 8, which extends beyond the bars 9 on itsinner faces and side faces.

The tie-rods 6 pass through the bars 2, and are fastened to the frame 9.The frame 9 with the bars 2, can be removed from the casing 8 wheneverremoval is necessary.

It will be understood that in stamping the bars 2, the tongue orprojection 3 must be punched somewhat farther away from the thin edgethan from the thick edge, so that the ridge or edge of each tongue 3 andthe bottom of each groove 4 will be parallel to a line joining themiddle points of the thick and thin edges of the bar 2, as shown in Fig.5. In this way, when the bars are arranged one upon the other, as shownin Fig. 2, they will form a straight row. The bars 2 are all made ofmetal, and for this purpose any metallic substance that will resistrusting and corrosion, such as nickel steel, can be employed. I

The manner in which my screen is used is shown on Fig. 1, .whereon 10 isthe mortar of a stamp mill containing a heavy stamp 11 operated by a rod12. 13 is an opening-into which the ore to be treated is fed, and 14 isan opening through which the crushed ore is discharged. My screen 1 isarranged in the opening 14, but does not fill the same, the space aboveit being filled by a board or the like. This board I do not deem itnecessary to show on the drawings. Both the board and the screen arereceived by grooves 15, along the sides of the opening. 14, and held inplace by a wedge-shaped locking member 16. Water is supplied through theopening 10 in the top of the mortar; The face containing the small endsof the openings, that is to say, the receiving face of the screen, is onthe inside of the crushing mill 10, and the discharge side,'whichcontains the large ends of the openings between the bars, faces outward.When in position, the wooden face of the casing 8 of the screen gives atight fit against the edges of the opening 14 in the mortar 10, whilethe outer or discharge faces of the casing 8, which is covered by theangle bars 9, affords a tight engagement to the wedge-shaped keys 16. Asthe stamp 11 reciprocates, it crushes the lumps of ore fed into thecrushing mill through the opening 13. The water fed in at the top issplashed against the receiving face of the screen and carries thepowdered ore in the form of pulp or mud against the thick edges of thebars 2. By arranging the bars with their thick edges on the inside, thewearing action of water bearing the crushed ore is resisted to a greaterextent, and, as stated above, the openings becoming larger toward theouter face of the screen, the liability of the screen becoming choked upby the crushed ore is reduced to a minimum. After passing through thescreen between the bars 2, the finely divided ore is delivered to theamalgamating plate or table adjacent to the opening 14:, on the outsideof the mortar 10, and the precious metals are retained. I do not deem itnecessary to show this amalgamating plate on the drawings.

I preferably make the bars three-eighths of an inch to one-half an inchwide, and onetwentieth of an inch tapering to one-fortieth of an inchthick, but I can make them of any size if desired. The tie-rods 6 passthrough openings about one-eighth of an inch in diameter, so that thereis at least one-eighth of an inch of plate to be worn through before thescreen becomes too impaired for use.

The ordinary size of my screen will be about twelve inches by fifty-twoinches on the outside of the casing, and about seven and one-half byforty-seven and one-half inches on the inside, making the face of thecasing 8 about two and onehalf inches wide. The grooves may be arrangedabout onehalf an inch apart, and the width of the openings is such thatabout nine of the bars or plates can be used to the half inch, makingtwo hundred and sixteen meshes or bars to the foot. By means of a screenso constructed, the wear is greatly reduced,- and at the same time thecapacity of the screen is greatly increased.

Obviously, changes in the shape and size of the parts within the scopeof my invention may be made when desired, it being understood that themain features of my invention comprise bars having their receiving endsespecially designed to resist wear, and having the openings therebetweenof such shape as to obviate the liability of the screen becoming choked,and being used in such number as to give the working capacity required.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. An article of manufacture for a stamp mill screen, consisting of abar or plate having fiat sides and having tongues projecting V from thefiat surface of one of said sides, said tongues being transverselyarranged with respect to said fiat sides. 7

2. An article of manufacture for a stamp mill screen, consisting of abar or plate, said bar or plate having tongues and grooves on the flatsides thereof, said tongues andgrooves being transversely arranged onsaid flat sides, and each tongue on one of the said flat sides beinglocated opposite a groove on the other flat side.

3. An article of manufacture for a stamp mill screen, consisting of abar or plate thicker along one edge than along the edge opposite, saidbar or plate having flat sides and having tongues thereon, said tonguesbeing transversely arranged with respect to said bar.

4. An article of manufacture for a stamp mill screen, consisting of aplate or bar thicker along one edge than along the opposite edge, saidbar or plate having flat sides and having tongues and grooves formed onsaid flat sides,'the said tongues and grooves being transverselyarranged with respect to said bar.

5. In a stamp mill screen, the combination of a frame and plates or barssupported by the frame, the said plates or bars having projections ortongues holding them spaced apart and having their edges on thereceiving face of the frame of greater thickness than the edges alongthe discharge face of the frame.

6. In a stamp mill screen, the combination of a frame and plates or barssupported by the frame, the said plates or bars having projections ortongues holding them spaced apart, and depressions forreceiving the saidtongues, and having their edges on the receiving face of the frame ofgreater thickness than the edges along the discharge face of the frame.

7. In a stamp mill screen, the combination of a frame and plates or barssupported by the frame, the said plates or bars having projections ortongues holding them spaced apart and having their edges on thereceiving face ofthe frame of greater thickness than the edges along thedischarge face of the frame, and tie rods for holding the bars or platestogether in the said frame.

8. In a stamp mill screen, the combination of a frame and plates or barssupported by the frame, the said plates or bars having projections ortongues holding them spaced apart and having their edges on thereceiving face of the frame of greater thickness than the edges alongthe discharge face of the frame, and tie rods for holding the bars orplates together in the said frame, said tie rods passing through thebars or plates and the projectlons or tongues thereon.

9. In a stamp mill screen, the combination of an outer casing, an innerframe consisting of angle bars fitting within the outer casing, platesor bars supported by the inner frame and spaced apart to form openingsbetween them, the plates or bars being of greater thickness at thereceiving face of the frame, so as to form openings increasing in sizefrom the receiving face of the screen to the discharge face, and tierods holding the bars or plates in position in the inner frame.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

DARIUS COMSTOCK EN EARL.

Witnesses:

GHAsE WITHROW, HENRY J. HAWLEY.

-Gopies of this patent may be obtained for five cents each, byaddressing the Commissioner of Patents,

Washington, D. G.

